Small-signal characteristics of InP Junction FET's

The small-signal scattering parameters and an equivalent circuit of InP junction field-effect transistors are presented. These transistors have a planar structure with the channel and gate regions formed by selective silicon and berylium implantation, respectively. The nominal channel thickness and doping are 0.2 µm and 10
¹⁷
cm
^-3
and the gate length is approximately 2 µm. Typical values of transconductance and I
DSS
are 50 mS/mm and 150 mA/mm. Scattering parameter measurements indicate an f
T
of 10 GHz and an
f_{\max}
of 22 GHz. In-process microwave measurements are used to determine the device performance before final gate definition.